1. Field of the Invention
This invention relates to quick set slurry seal emulsions. More particularly, it relates to novel emulsifiers for solventless and solvent containing, mixing grade, oil-in-water cationic bituminous emulsions, which emulsifiers are the reaction products of alkyl phenols, aldehydes and polyamines.
2. Description of Related Art
In paving operations, three main practices are employed to achieve thorough mixing of bitumen and aggregate:
(1) Mixing of free flowing heated asphalt (asphalt cement) with pre-dried aggregate; PA1 (2) Mixing pre-dried aggregate with asphalt diluted with a hydrocarbon solvent (cutback asphalt, cutter stock) at ambient temperatures; and PA1 (3) mixing aggregate with asphalt emulsions, e.g., oil-in-water emulsions, obtained by vigorous agitation of asphalt and water in the presence of an emulsifying agent.
Because of increasing cost in energy and hydrocarbon solvents and because of environmental concerns, the use of emulsified asphalt is increasing.
Conventionally, emulsion slurry seals are formulated from mineral aggregate, which is a fine stone aggregate and/or mineral filler and a mixing-grade, quick-setting or slow-setting emulsion containing bituminous residue (usually asphalt) and water to attain slurry consistency. Usually, densely-graded aggregates, such as granite screenings, limestone screenings, dolomite screening and blast furnace slag, are combined with bituminous emulsions to produce slurry seal compositions.
When a slurry seal is used in paving and road maintenance, the mixture of emulsified bituminous material and fine-grained aggregate is held in suitable suspension until applied to the road surface. The slurry seal emulsion is of an oil-in-water type.
Depending on the emulisfier used to achieve an emulsion, anionic or cationic emulsions are obtained. In anionic emulsions, asphalt droplets are negatively charged; in cationic emulsions, the asphalt droplets bear positive charges.
In a bituminous emulsion formulated using cationic emulsifiers the bituminous material is deposited from the emulsion on siliceous or granitic aggregate surfaces due to the attraction of polar charges between the positively charged bituminous droplets and negatively charged aggregate surfaces.
Cationic emulsions have been obtained by employing a variety of nitrogen containing organic compounds, such as fatty amines, fatty diamines, fatty triamines, fatty amidoamines, fatty imidazolines, and reaction products of all these compounds with ethylene oxide and fatty mono- and diquaternary ammonium salts. The fatty radical of these compounds can have a variety of chemical structures, and the building blocks for the preparation of these amines can be obtained from a variety of sources, such as petroleum refinates, animal fats, vegetable and fish oils, and tall oil. Amidoamines suitable as emulsifiers are disclosed in U.S. Pat. No. 3,230,104 to Falkenberg and in U.S. Pat. No. 3,097,174 to Mertens. Combinations of fatty monoamines and triamines are disclosed in U.S. Pat. No. 3,738,852 to Doi; fatty diamines are disclosed in U.S. Pat. No. 3,728,278 to Trameli and U.S. Pat. No. 3,581,101 to Gzemski; fatty quaternary and diquaternary salts and modifications thereof are disclosed in U.S. Pat. No. 3,220,953 to Borgfeldt, U.S. Pat. No. 3,867,162 to Elste, U.S. Pat. No. 3,764,359 to Dybalski, U.S. Pat. No. 3,957,524 to Doughty and U.S. Pat. No. 3,466,247 to Ohtuka, and fatty imidazolines are taught in U.S. Pat. No. 3,445,258 to Ferm. The use of tallow quaternary ammonium salts and tallow diquaternary diammonium salts for making emulsions suitable for slurry seal in solventless applications is described in U.S. Pat. No. 3,764,359 to Dybalski.
The uses of acidified reaction products of certain polycarboxylic acids, anhydrides, sulfonated fatty acids and epoxidized glycerides with certain polyamines as emulsifiers yielding asphalt emulsions which can be mixed with fine grained aggregate to give workable aggregate/emulsion mixes are disclosed in U.S. Pat. No. 4,447,269 to Schreuders et al., U.S. Pat. No. 4,450,011 to Schilling et al., U.S. Pat. No. 4,547,224 to Schilling et al., U.S. Pat. No. 4,462,890 to Schilling et al., U.S. Pat. No. 4,464,286 to Schilling, U.S. Pat. No. 4,561,901 to Schilling, U.S. Pat. No. 4,597,799 to Schilling, and U.S. Pat. No. 4,676,927 to Schilling et al. The use of a quaternary amine obtained by reacting epicholorohydrin, trimethylamine and nonylphenol for solventless mixes is disclosed in U.S. Pat. No. 3,957,524 to Doughty.
Quick-setting bituminous emulsion compositions wherein amine and alkanolamine salts of alkylbenzenesulfonic acid are used as emulsifiers are disclosed in the U.S. Pat. No. 4,657,595 to Russell.
The general object of this invention is to provide novel versatile cationic emulsifiers for solventless and solvent containing, rapid setting, mixing grade, oil-in-water bituminous emulsions.
Another object is to provide a cationic bituminous emulsion for mixing with aggregates whose coating characteristics and set time can be varied.